Daihatsu Feroza Problems

Even the newest Daihatsu Feroza is 20-years-old now so they're verging on classic car territory, and this means many will require engine and transmission overhauls, if not even bigger work. Coupled with the fact they are renowned as hardy off-road 4x4s the chances of finding one which hasn't had a hard life is going to be extremely difficult.

All that considered, however, they are well-made and generally reliable vehicles when in good operating order.

From its 1989 introduction until its cessation in 1998, the Daihatsu Feroza was only available with petrol 1589cc four-cylinder engines.

While specific tyre sizes will depend on what wheels are fitted to the exact Feroza in question, the popular short-wheelbase Daihatsu 4x4 should normally take a 225/70 R15, though a 205/75 or even a 195/75 could potentially be fitted in certain circumstances.

Check what size tyres are on your car now by looking on the side of the tyre for similar numbers as 225 refers to the width in millimetres, 70 or 75 will be the height of the sidewall of the tyre (known as aspect ratio), while 15 refers to the wheel diameter in inches.

The Daihatsu Feroza (called the Rocky or SporTrak overseas) was sold in part-time 4x4 or full-time 4x4 variants depending on the gearbox chosen.

Daihatsu Ferozas carried a kerb weight of 1206kg when new.

Your list of potential causes is a pretty sharp one and one that suggests you know a bit about how engines work. And it remains that all those possibilities could be the root cause of your problem.

If petrol is getting into the sump, it’s going to be past the piston rings, which means you either have a leaky component in the fuel system (that’s dribbling fuel into the engine when it’s not running) or, as you suggest, something like a dud temperature sensor which is creating a too-rich mixture that is not burning completely and contaminating the engine oil in the process.

Having the car scanned might throw up a fault code that coincides with one of these components, and that would be a very good place to start. But don’t rule out the really basic stuff, too, like a worn out engine or a broken piston ring that is allowing fuel to enter the sump. Or perhaps the car is used exclusively for short trips where the constantly cold operating temperature is leading to an equally chronic rich-mixture state.

Meantime, you’re right to not drive the vehicle until this is fixed as the thinned oil now in the sump can’t protect the engine as well as it needs to, leading to accelerated engine wear.